Colony stimulating factors are a group of cytokines that have the desirable property of enhancing marrow production of granulocytes and macrophages. These cytokines might be of great interest to oncologists if they are capable of increasing peripheral blood granulocyte counts without significant associated toxicity in patients receiving myelosuppressive therapy. This study is a phase I evaluation of recombinant human GM-CSF. Patients with solid tumors with reasonably intact bone marrows will receive escalating doses of GM-CSF in an attempt to determine the maximally tolerated dose and the dose at which significant increases in peripheral blood granulocyte counts and granulocyte and monocyte function can be observed. Only 1 patient has been admitted to this trial to date, and no comment can yet be made as to toxicity or antitumor effectiveness.